Use smart-link SDK instead of custom made tag helper

[PetrSvirak]

Motivation

The project currently uses a custom-made tag helper that allows for opening Kontent UI after a click. It would be superb if it could leverage kontent-smart-link SDK and so Dancing Goat was made Web Spotlight ready.

Proposed solution

Use UMD bundle instead of currently used (EditLinkTagHelper)[ https://github.com/Kentico/kontent-sample-app-net/blob/master/DancingGoat/TagHelpers/EditLinkTagHelper.cs].

Additional context

• https://github.com/Kentico/kontent-smart-link
• https://docs.kontent.ai/tutorials/develop-apps/build-strong-foundation/set-up-editing-from-preview
• https://docs.kontent.ai/tutorials/manage-kontent/projects/set-up-web-spotlight
• 

[Simply007]

Related branch: https://github.com/Kentico/kontent-sample-app-net/tree/webspotlight